Method of making welded pipes.



I. L. PINKHAM. METHOD 0F MAKING WELDED PIPES.

APPLIGATIQN FILED una, 19134 1108,393 Patented Aug. 25, 1914,

N ik Q' u. s @9T 'LL v S' W im h' m S I m d l Y E N WITNESSES f I INVENTOR v VUNTTED STATES PATENT oEEreE.

FRANK L. PINKHAM, or' WILKINSEURG,

PENNSYLVANIA, xSSIGrNORy TO THE NA- TIONAL TUBE COMPANY, OF PITTSBURGH, FENNSYLVQANIA, A CORPORATION OF NEW JERSEY.

ToaZZ whom t may concern:

of Wilkinsburg, in the county of Allegheny and State of'Pennsylvania, have invented a new and useful Method of Making Welded Pipes, of which the following is a specification. i

My invention` relates to the manufacture of welded pipes and tubes, and, while not restricted to suchuses, more particularly relates to the manufacture of the smaller sizes of such materials. Heretofore, in the manufacture of welded pipes and tubes, it has been the p-ractice to butt-weld thelongitudinal edges of the skelp in making the smaller sizes (up to two inches in diameter) by drawing the skelp through a welding bell. With the larger sizes of pipes and `tubes (above three inches indiameter) the longitudinal edges of the yskelp are scarfed and bent into cylindrical form with overlapping scarfed edges. The overlapping edges of the bent pipe skelp are, after being heated to a welding temperature, then lap-welded by means o-f welding rolls, a welding ball being employed in conjunction with 4the 'welding rolls to form the internal support required for they inner surfaces of the pipes in making lap-welded pipes. The butt-weld and the lap-weld processes are both employed in making pipes and tubes of from two to three' inches in diameter, the particular kind Aof pipe determining the processes used." The welded pipes, while still heated 'from the welding operation, are then Isubjected successively to the action' of sizing rolls to fix the' external diameter, and cross rolls' to straighten the pipes, after which the pipes are cut to length and allowed to cool in readiness to be threaded' or to be transferred to a place of storage or shipment.

One object of my invention is to provide an improved method of making welded pipes or tubes in a novel series of steps whereby the pipe skelp is more' easily formed into pipe, and the liability of forming pipes having imperfect welds is lessenedfand prevented.

Another object ofthe invention is t0 prol vide a novel method of making welded pipes by the use of which variations in wall thickness and in the internal and external diame' ters of the pipes are avoided and prevented METHOD or MAKING WELDED r'rPEs.`

spec'ication'of Letters Patent. Patented Aug- 25, 1914. Application filed February 2, 1913i Serial No. 747,020.

.y anda more uniform product of standard di- Be 1t known that I, FRANK L. PINKHAmf a citizen 'of' the United States, and' resident -mensions and having an improved surface ffinashis produced, and the difficulties met with in making small welded pipes as manufactured heretofore are largely avoided and overcome. v

The invention consists. in first forming and welding a pipe 'skelp into a tubular.y

blank of a diameter materially greater thanr that ofthe finished pipe, and then, preferably immediately after and while still heated from the welding operation, subjecting the heated tubular blank to the action of the reducing rolls of a rolling mill by which the tubular blank is reduced to the desired standard internal and vexternal ydiameters and wall thickness or gage'and finally cross rolling the pipe to straighten the welded rolled pipes.

Referring'4 to the drawings forming part of this specification, Figure l is a plan showing diagrammatioal'ly'one arrangement of apparatus adapted for use in carrying out .my invention. `Fig. 2 is a side elevation cylindrical passes therebetween.

In the accompanying drawings the numeral 2 designatesa welding furnace and 3 1s a draw-bench on which the skelp, as removed'from the furnace, are formed in to tubular blanks by drawing the heated skelp through the welding bell removably secured on the forward or furnace end of the drawbench. The draw-bench is of the usual Aknown construction having an endless draw- `draw-'bench 3 along one side thereof lis a' 'trough or conveyer 5 and located betweenv the draw-bench 3 and conveyer 5 1s aA series E of skids forming a transfer table 6 onwhich the welded skelp or blanks'are transferred from the draw-bench to the conveyer 5. Atthe rear' end of 'the trough or conveyer 5 is a series of sets of two-high rolls forming a continuous rolling mill in which the welded blanks are rolled in carryingout the steps of my improved method.

The rolling mill as shown comprises a v pair of reducing rolls 7, 7 having an elliptiblank. 'The so-formed tubular blanks are ing mill upsetting or thickeningthe wall having the desired external and internal cal reducing pass 8, as is illustrated in Fig.

3) the axes of the rolls being arranged to extend at an angle to the horizontal, a pair of rolls 9, 9 having an elliptical pass 8 similar to that shown in Fig. 3 with the axes of Lthe rolls 9, 9 extending at the opposite angle to the horizontalv to that of the rolls 7 7 and a third pair of rolls 10,10 havingia cylindrical pass 11 formed therebetween, (as shown in Fig. 2) the axes of the rolls 10, 10 preferably.y being inclined at an angle to the horizontal as shown.

A trough or conveyer 12 extending lengthwise between the rolls 7 and 9 is employed to deliver the blanks from the rolls 7 to the rolls 9, and a similar trough 'or conveyer 13 extends between the rolls 9 and 10 for a similar purpose. v

On the discharge side of the rolls 104 a stand of cross vrolls 14, 14, of the usual yknown construction is located, by which the pipes are straightened, a conveyer 15 being employed to deliver the pipes from the reducing rolls 10 to the cross straightening rolls 14 and a similar trough'or conveyer 16 is employed to receive the pipes delivered from the cross rolls 14. A series of skids is employed alongside the conveyer 16 to form a receiving table 17 to which the straightened pipes are trans-A ferred from the conveyer `16 and are stored until removed to the saws 'or other apparatus used in cutting the pipes to length, or to a place of storage or shipment.

In carrying out the steps of my improved method the pipe skelp are charged into the welding furnace 2 and, when heated, are successively removed from the welding furnace and drawn through the welding bell positioned on the front or furnace end of the draw-bench 3, the longitudinal edges of the skelp being thereby forced into engagement and welded together to form a tubular o f materially larger diameter than that desired in'. the finished pipe, and may be of somewhat less thickness or gage than is re-l quired in the finished pipe.

The so-formed tubular blanks are, prefer-l ably immediately after and while still heated from the welding operation, then caused to pass throughv the stands 0f reducing rolls 7, 7 9, 9, and.` 10, 10, in which the blanks are reduced in'diameter to form the pipe to the desired external diameter, the reducing operations in the rolls of the rollof the pipe so as to produce or form a pipe diameter'l and wall thickness or gage. rllhe License which they are transferred sidewise to the skids forming the cooling bed 17. The pipes are then transferred from the bed 17 to a saw or other apparatus employed and, after being cut to length, are delivered to a place of storage or shipment. y

So far as I am aware, I am the first to disclose a method of making pipes in which the skelp are first welded into blanks oflarger curately formed to diameter and wall thick' ness, and the finish on the internal and external surfaces is very much better than Vthat obtained by the old method of' making such pipes, while the number of defective pipes having imperfect welds and other defects or faults is'greatly decreased.

Modifications in the construction and ar rangement of the apparatus used in carry? ing out my invention may be made without departing from my invention as defined in the appended claims.

I claim:

1. rIlhe method of making-welded pipes which consists in welding a pipe skelp to form a tubular blank having an external diameter materially greater than that of the nished pipe, and then. rolling the tubular blank in the reducing pass of a rolling mill to thereby reduce the pipe to diameter.

2. The method of making welded pipes consisting in welding a pipe skelp to form av tubular blank having an external diameter materially greater and a wall thickness less than that of the finished pipe, and then rolling the tubular blank in the reducing pass of a rolling mill to thereby form the .pipe to diameter and wall thickness.

3. The method of'making welded pipes consisting in welding a pipe skelp to form a tubular blank having internal and external diameters materially greater than those ofthe finished pipe, and then rolling the welded tubular blank in a rolling mill lto thereby reduce the pipe tol diameter.

4. The method of making welded pipes which consists in welding a pipe skelp to form a tubular blank havingan external diameter materially greater than that of the finished pipe, then rolling the tubular blank in a series of the reducing passes of a rolling mill to thereby reduce the pipe to diameter, and then cross rolling and thereby straightening the rolled pipe. y

' 5. The method of making welded pipes consisting in Weldinga pipe skelp to form a tubular blank having an external diameter materially-greater than that of Ithe finished pipe, then rolling the welded tubular blank to thereby form the pipe to diameter, and

then cross rolling and thereby straightening the rolled pipe. 10":

In testimony whereof, I have hereunto set my hand.

FRANK L. PINKHAM. Witnesses:

HENRY J. GRAND, M. R. EVANS. 

